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Home My WebLink AboutBRATSLAVSKY S12101 Onsite File Bratslavasky #512101 Engineer's Soils Report Proposed Subdivision of T12N, R3W, Sec 33, LOT 210 Municipality of Anchorage Prepared for: Roman &Tanya Bratslayski 15300 Old Seward Highway Anchorage, AK 99516 Prepared By: Pannone Engineering Services, LLC P.O.B. 100217 Anchorage, AK 99510 Submitted By: .•`t, r 114 • �.%n Steven R °Jnn.;ne: I f No CE 8149 r�� 1� •.., .,•,• Steven R. Pannone, P.E. Principal, Civil Engineer July 28, 2014 T12N, R3W, Sec 33, Lot 210 Engineering Report Project Description This soils report is to identify the suitability of the soils on the lot being subdivided for an on-site septic system. This subdivision is part of T12N, R3W, Sec 33, Lot 210. This report will detail the soils encountered during the soils investigation, existing topography, impact to surrounding wells and septic system and the suitability of the soils encountered for the use of an on-site wastewater disposal system and water supply system. The proposed lots will be approximately 2 acres and 1..6 acres in size. One new lot will have the existing house with existing well and septic; therefore a single test hole is required on the proposed undeveloped lot. Soils Investigation Pannone Engineering Services performed a soils investigation on July 15, 2014 on lot 210 in the area that the subdivided lot will be located. The test pit was excavated by the A+ Home Services and were excavated to the maximum extent of the excavator or until refusal. The test pits revealed a variety of soils. We found in the test pit located on the proposed western lot, a one half foot thick layer of organics, underlain with a brown colored, silty sand and gravel. A percolation test was performed on the soils at a depth between four and five. The soils have a percolation rate of 24 minutes per inch (mpi). We did not encounter bedrock in the test pit. Permafrost was not encountered in the test pit nor is it suspected in this area. Groundwater was not encountered during excavation nor after the seven day monitoring period. Topography The lot to be subdivided is bisected by a steep slope, which will be divided into an upper lot and lower lot. The existing single family home with its well and septic system are located on the upper portion of the lot. The proposed undeveloped lot is located at the toe of the slope. Generally the area, other than the steep slope, slopes at 5%to the south west. Existing water and wastewater systems The proposed subdivision is located along Old Seward Highway. The lot is bounded to the north by Rabbit Creek Road and Old Seward Highway. There are developed lots along the western T12N, R3W, Sec 33, Lot 210 and southern sides of the lot. The existing water supply systems are private wells and have a 100 foot protective radius around them (i.e. a new wastewater disposal system may not be located less than 100 feet from these private water wells.) The wells are far enough back on the lot that their protective well radiuses do not affect the proposed lots. Water Availability The surrounding wells are typically 70 to 100 feet deep. The static water levels range between 50 and 80 feet deep. The existing well flow data that was available showed that the wells with record data could produce approximately at least 10 gallons per minute at a depth of 70 to 100 feet. Based on the record research and field data we collected, there appears to be adequate water available for the proposed subdivision without affecting the surrounding wells. The well will be approximately 70 to 100 feet deep and will produce at least 6 gallons a minute, which is above the minimum requirement established by the MoA well Code (AMC 15.55). Installing these wells will not affect the production of water wells on the surrounding property. Surface water Rabbit Creek is located 100 feet from the proposed septic reserve area at its nearest point. Engineering Criteria The soils in this area are typically organics underlain by silty gravel and sand. PES conducted a percolation test on the proposed lot and found a percolation rate of 24 minutes per inch. The soils encountered on Lot 210 are average percolating soils (15-30 mpi) and an application rate of 0.6 gpd/sf should be used for the design of a wastewater disposal system on Lot 210. Site Information For a subdivision, a site plan stamped by an engineer must show specific areas for the septic system based on the observed percolation rate and Title 15.65.180, Table 2. These areas must meet all set back requirements of Title 15.65. Lot 210 has a percolation rate of 24 min per inch (MPI). According to Table 2, and area of 14,000 sf must be shown. The attached site plan shows the 14,000 sf required for Lot 210.. The Municipality of Anchorage (Moa) Regulations (15.65) govern for single-family homes. These regulations require a minimum of four (4) feet vertical separation between the bottom of a soil absorption system and ground water for a conventional wastewater disposal system, six feet (6') to bedrock or other impermeable layers (tight silts and clays) and must be located greater T12N, R3W, Sec 33, Lot 210 than 100 feet horizontally from any surface water (Creeks and ponds). Additionally, the accepting soils must have a percolation rate of less than 120 minutes per inch. A lot must have room for a primary and reserve soil absorption system. Based on the existing topography, soils investigations conducted to date and record research of surrounding lots, the proposed lot has in excess of 14,000 sf of contiguous area suitable for an initial and replacement for conventional wastewater disposal systems. WELL (E) STATIC: 52 \ 400r DEPTH: 79 j PRODUCTION: 15 GPM \ qO�O c4 i \ tiro 0� 06, / 203 i i \ 105.7 _ Z�• \ \ITH-1 \� I •• f 14.000 S.F. SEPTIC \ \ \ \ Q\/ \,\,\._.64- .. \ 1 /� • RESERVE AREA �: �M_s,C,— F. I \ ' i l_ \ //9eq \• G 95. 209 �•�"l —� i'��1 s� \\ �` 1.. c f _ WELL (E) V'STATIC: 51 UNDOCUMENTED WELL (E) I . 1 ' WELL P \ \\ PRODUCTION: 6+ GPM I'\ i I \ I i a \ • I w i, SEPTIC (E) . HOUSE (E)% I I \ II N- - . ..• _ , ,,. 1 �� I ' I -off/ I I \ • 01I \ TH-2-' •I J 33' ROADWAY rDWAY EASEMENT 'I \ (BY OTHERS):: .._.__._.—i._._._._._._.—.� T.D.: 7' - DRY 1 I C - D r SEPTIC AREA (E)J I , ' - 1 - \ . C3 . 232 1 -- .--....' . . 8 (G WELL (E) I \ STATIC: 70 I s DEPTH: 97 PRODUCTION: 10 GPM I I 2 s �W€LL(E) NOTES: PANNONE ENG SVC, LLC �- - OF At\k% Date 014 SOILS LOG P.O. BOX 100217 ANCHORAGE, AK 99510 ��P" ,:its,44 Scale PHONE (907) 272-8218 FAX (907) 272-8211 ;or* .. *+�, t•ltoo' .... ... . . P.I I). NO T12N, R3W, Sec33, LOT 210 .. 18-322-04 ROMAN & TANYA BRATSLAVSKI Steven . Ponnorae / PERMIT NO. .15300 OLD SEWARD HIGHWAY /+,� .• CE 8149 .•ter/ OSPXXXXXX PLAN ANCHORAGE, AK 99516 ti>1 ,e:• S�O�a� 'r Sheet 2 JIJILJ LL)t - I"CIKI..IJL/1 I RAN ICJ I TEST HOLE 1 OR ORGANICS SLOPE A:E PLAN k' / •\. / \ \\ �� x \ H—t \ �\/S.----R--------------- � TH 7/ i T \ \ / ��\ \ \% \�\ GM/SM SILTY SAND \ /\ AND GRAVEL \ �% J \ • WAS GROUND WATER SLOPE ENCOUNTERED? N IF YES,AT WHAT TH DEPTH? -DRY x DEPTH TO WATER AFTER BOH MONITORING? -DRY DATE: 7/25/2013 1 10/17/14 Dry WATER READING DATE CLOCK NET TIME LEVEL NET DROP TIME READING 1 7/15/14 3:20 - 5.24 - 2 3:50 30 MIN 6.84 - TE PERFORMED:7/15/14 3 3:50 5.24 - 4 4:20 30 MIN 6.50 - 5 4:20 - 5.24 - 6 4:50 30 MIN 6.48 - PEROLATION RATE 24 (min/inch)PERC HOLE DIAMETER 6 inches TEST RUN BETWEEN 4 FT AND 5 FT 'MMENTS: Test hole excavated by A+ HOME SERVICES. RFORMED BY: Steven R. Pannone, P.E. I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE TH ALL STATE AND MUNICIPAL GUIDLINES IN EFFECT ON THE DATE OF THIS TEST. NOTES: PANNONE ENG SVC, LLC :-„N....NA.,A� D028/20,4 > LOG P.O. BOX 102954 ANCHORAGE, AK 99510 'S •'• '•••'qS 4 �'<P' ' ••...q. Scale _ PHONE (907) 272-8218 FAX (907) 272-8211 i g.• y �� NTS 1 * / ..* I .. .. . ..� ... � .. • 9 P.1.0. NO T12N, R3W, Sec33, LOT 210 a :- 22-04 ROMAN & TANYA BRATSLAVSKI 1 Leven R. Pannone/ PERMIT NO. 15300 OLD SEWARD HIGHWAY I+ •FJ CE 8149 � oSPxxxxxx SOILS LOG ANCHORAGE, AK 99516 ,1�>11' OFESSO- Sheet 2